1. Field of the Invention
The present invention relates to a semiconductor laser device.
2. Description of Related Art
Japanese Unexamined Patent Application Publication No. 2009-94360 discloses a semiconductor laser device according to a related art. The semiconductor laser device includes a substrate and a group III nitride semiconductor laminate structure formed on the substrate. The group III nitride semiconductor laminate structure is arranged by laminating an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer. The n-type semiconductor layer includes an n-type AlGaN clad layer and an n-type GaN (or InGaN) guide layer, while the p-type semiconductor layer includes a p-type AlGaN electron blocking layer and a p-type GaN (or InGaN) guide/GaN contact layer. A p-type transparent electrode made of ZnO is in ohmic contact with the surface of the p-type GaN (or InGaN) guide/GaN contact layer. The p-type electrode is used also as an upper clad layer.